Packing ring



July 10, 1962 H. w. FARREY PACKING RING Filed March 4. 1960 IN VEN TOR. /Vdra/J X277@ BY 3,643,436 PACKING RING Harold W. Farrey, Racine, Wis., assignor to Walker Manufacturing Company, Racine, Wis., a corporation of Delaware Filed Mar. 4, 1960, Ser. No. 12,806 3 Claims. (Cl. 210-484) This invention relates to filter cartridges and, in particular, refers to the type of lter unit in which a compressed lter media is confined within a receptacle.

`Fibrous materials of various types are often used as a filter media in oil :filters and filters for other Iapplications. It is usually desired to compress this material to a certain extent so :as to obtain suicient density for proper filtration, and also to prevent by-passing around the ends of the lter media. This has' created a problem,

particularly when waste material is inserted in can-type containers, because so much waste material is inserted to obtain the proper density that it was extremely diicult, if not impossible, to use all the required Waste material and still be able to attach the end cap on the container. The waste material springs back beyond the end of the can and makes it extremely ditlicult to fit the end cap in place `and attach it to the end of the can.

'Ihe present invention overcomes this diiculty by means of 1a packing ring which is snapped in place in the end of the can and engages ta portion ofthe Waste material that is exposed and holds it in compressed condition. The remaining portion of the Waste engages the end cap, which can now be mechanically or otherwise secured to the end of the can, and provides enough pressure to prevent by-passing.

'Ilhe invention is illustrated in the accompanying drawings in which:

.FIGURE 1 is a vertical crossfsection through a typical filter cartridge employing Waste material and utilizing the retainer ring of this invention;

FIGURE 2 is an enlarged view of the structure shown within the circle 2 in FIG. 1; and

FIGURE 3 is an enlarged View showing one stage in the process of inserting the Waste material in the lilter can. f

In FIG. 1 the filter cartridge 1 lhas an outer metal Shell 3 which is perforated. The opposite ends of the shell 3 `are closed by top `and bottom end caps 5 and 7, respectively, which are interlocked in joints 9 and 11, respectively, with the top and bottom ends of the container 3. Extending between the end caps and 7 is a perforated center tube 13. It is held in place by the pressure of the end caps. Clamped between the top of the center tube 13 andthe top end cap 5 is a bracket 15 that carries la grommet or bushing 17. This is aligned with a bushing 19 that is carried by the bottom end cap 7, the two bushings or grommets 17 and 19 serving to engage a suitable standpipe (not shown) in the lter device in which the cartridge 1 is inserted. A sheet of Atissue paper 21, shown considerably exaggerated in thickness in the drawings, may be wrapped around the center tube 13, and, if desired, a Isimilar sheet of tissue paper 23 may be wrapped around the inside of the container 3 to cover the perforations in it. A handle 25 may extend through suitable openings in the top end cap 5 and be supported by it. Within the annular space 27 defined by the center tube 13 and the container 3 is packed the iilter media 29, in this case a compressible fibrous waste type material available on the open market.

The waste material 29 is inserted in the can 3 at a stage of assembly in which the bottom end cap has been attached to the container 3 and the center Itube 13 has been inserted but the top end cap 5 is not attached in joint 9 to the container 3, i.e. the top of the can is open. At this stage it is possible, obviously, to insert the waste material 29 into the space 27 by funneling it in through the top of the can. In order to obtain the vrequired density for proper ltration, and yalso to prevent by-passing around the interface between the waste material and the top and bottom end caps it is ordinarily necessary to insert 'a considerably greater volume of material than would, if uncompressed, `occupy the volume of the space 27. Thus, it is necessary by means of a ram 31 to cornpress the material 29 into the space 27. When this is done, however, the material will spring back the moment pressure of the ram 31 `is removed. When this occurs it is extremely diflicult `or impossible lto force the end cap 5 in proper position so that it can be attached to the end of the can in the joint 9, said joint normally being formed by means of conventional spinning tools'.

In yaccordance with the invention the packing or retainer ring 33 which is of the same diameter `as the inner diameter of can 3, is placed on top of the waste material under the ram 31 and pressed by it downwardly unit it snaps under a series of dimples or sheared tongues 3S that are pressed or sheared in the Wall of the container 3. They hold the ring 33 `against upward displacement and when the ram 31 is removed the packing ring 33 will 'hold the material 29 in place, particularly around the outer periphery, so that the cap 5 can be put in position and interl-ocked at 9 with the end 37 of the can 3. When conlined under pressure in this manner the fibrous material 29 will bear against the inward faces of the end caps 5 and 9 and prevent by-passing of oil along these faces from the can 3 to the center tube 13 and force the oil to pass through the fibrous material 29.

Various -modications are Within the scope of the invention. For example the ring need not touch the entire periphery of the wall and can be of wire form. Also it can be secured to the center tube instead of lthe outer wall.

I claim:

1. The method of packing compressible lter material in a tubular container comprising positioning a retainer ring ybetween the material and a compression ram and utilizing the ram to force the material into the container and the ring into the container until the ring snaps behind the shoulder on the container to hold the material compressed in the container, removing the ram from the container, and attaching an end cap to the container over the ring.

2. In a filter unit, a container having a wall deiin-y ing la chamber, compressed filter material filling the 3 K adjacent the retainer member and defining an end of the chamber. y

3. A filter unit ycomprising a container having a chamber, compressible material conned under compression in and completely filling the chamber, said container including a tubular member and an end cap closing at least a part of the end of the tubular member to pro-vide one end of the chamber, and la lter material retainer in the ychamber attached to the tubular member and engaging the end cap and the lter material and holding the material under compression.

References Cited in the le of this patent UNITED STATES PATENTS 'Jenkins July 13, 1909 Cook Apr. 3, 1951 Wilkinson Feb. 5, 1952 Rodwell Mar. 3, 1953 -Wilkinson May 6, 1958 FOREIGN PATENTS Canada Dec. 1, 1959 

